1. Field of the Invention
This invention relates to the field of ventilating, heating and/or air conditioning units, for a vehicle passenger compartment in particular, and specifically to the field of auxiliary electric heaters equipping such units. The object of the invention is a frame for holding heating elements that such a heater comprises.
2. Description of Related Art
Ventilating, heating and/or air conditioning units, such as those for vehicles, commonly comprise an additional electric heater. A heater such as this is intended, in particular, to produce almost immediate auxiliary heat in vehicles deficient in heat upon start-up.
Supplementary electric heaters include a frame for holding electrical components and a connector for connecting the heater to an electrical power supply of the vehicle, or even also means for monitoring and/or controlling the operation of the heater. The frame generally has an overall planar, box-like shape, which, inside of its internal hollow space, houses the heating elements, such as positive temperature coefficient (PTC) resistors.
The basic problem is posed of designing the simplest possible frame structure, in order to reduce the costs of producing and assembling the heater components.
For example, according to the publications EP 0901311 (BEHR Gmbh & Co.) and FR 2838599 (VALEO CLIMATISATION), the frame is made up of two planar frame elements assembled parallel to each other, between which the heating elements are held. In a first phase, the latter are assembled together so as to form a single unit, which is installed on one of the frame elements. The other frame element is then assembled to the preceding one in order to hold the heating element unit together. The frame constitutes not only a member for holding the heating elements together, but also an intermediate member for positioning these heating elements inside of the unit, and, in particular, inside a housing that the latter comprises. For this purpose, the frame is equipped with means for connection to at least one wall of the unit, so that the airflow circulating inside of the unit passes through its overall plane, and in particular through its two opposing large faces.
A frame design such as this results in the implementation of a significant number of parts, and a significant number of operations for assembling these parts for the heater assembly. Furthermore, such arrangements are inconsistent with the use of standard heating elements. The ways and means for manufacturing the frame should be improved so that it can be obtained at low cost, while at the same time facilitating the installation of the heating elements onto the frame and the positioning and holding of these heating elements in relation to each other and in relation to the heater connector.